2′-deoxy-cytidine or its homologues as a medicine has good effect on treating viral diseases and cancer. At the moment, researches on this kind of compounds are attracting great interest in the art. Among these compounds, 2′-deoxy-2′,2′-difluoro-β-cytidine hydrochloride (Gemcitabine hydrochloride), i.e. β-1-(2′-deoxy-2′,2′-difluoro-D-ribofuranosyl)-4-aminopyrimidine-2-one hydrochloride is relatively well known, which has the following structure:

There are many methods for synthesizing β-1-(2′-deoxy-2′,2′-difluoro-D-ribofuranosyl)-4-aminopyrimidine-2-one hydrochloride but it is mainly synthesized by the method using D-glyceraldehydes as the raw material and bromodifluoroacetate as the fluorinating agent. The method was described in detail in literature such as Hertel, L. W. et al., J. Org. Chem. 1988, 53:2406 and Chou, T. S. et al., Synthesis 1992, 565. β-1-(2′-deoxy-2′,2′-difluoro-D-ribofuranosyl)-4-aminopyrimidine-2-one is a chiral compound. In the course of synthesis of using D-glyceraldehyde as the raw material, Reformasty reaction will be involved and the Reformasty reaction is a non-stereoselective reaction. In the preparation of the key intermediate 2-deoxy-2,2-difluoro-D-ribofuranose, it is not easy to control the stereoselective reaction. At the same time, in the course of synthesis, low boiling point anhydrous ether free from oxygen should be used as the reaction medium and the steps such as crystallization in solvent for resolution of isomers etc should be taken. As a result, both the yield and controllability of the reaction intermediate are low. Therefore the said method of synthesis seems to be not repeatable and not suitable for large-scale preparation.